Diurnal and seasonal influence on the indoor radon levels in dwellings of Sharjah Emirate as well its estimation of annual effective dose

Radon, a proven highly carcinogenic gas, has raised serious concerns, necessitating its measurement in residential areas. In the coastal city of Sharjah, United Arab Emirates (UAE), the first indoor radon concentration measurements were conducted. Following the Environmental Protection Agency (EPA) protocol, active radon detectors were employed in the living rooms of houses across the south-east region of the city. Measurements revealed that, the mean values during winter are of (39.6 ± 12.2) Bq/m3 (floor 1) and (35.7 ± 9.8) Bq/m3 (floor 2), while in summer, levels were slightly higher on floor 1 (55.8 ± 10.1) Bq/m3 compared to floor 2 (47.8 ± 12.6) Bq/m3. Ground floor analysis showed mean values of (57.0 ± 12) Bq/m3 in summer and (49.0 ± 16) Bq/m3 in winter. Higher summer levels were linked to climatic conditions and increased time spent indoors. The excess lifetime cancer risk for ground floor radon was estimated as 0.341% over 25 years. Annual dose equivalent was calculated using International Commission on Radiological Protection (ICRP) and United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) models. The calculated results were found to range from 1.7 to 3.0 millisieverts (mSv), which is within permissible limits. [Display omitted] •First-ever indoor air quality assessment in Sharjah.•Radon concentrations vary with diurnal and seasonal factors.•Mean radon values were higher in summer (60 Bq/m3) compared to winter (44 Bq/m3).•Ground floor radon values of summer month (68 Bq/m3) surpassed those on floor 1 in summer.•The annual dose equivalent ranged from 1.7 to 3.0 mSv.